WO1995009324A1 - Tuyau de generateur de vapeur a structure interieure nervuree et generateur de vapeur approprie a son utilisation - Google Patents

Tuyau de generateur de vapeur a structure interieure nervuree et generateur de vapeur approprie a son utilisation Download PDF

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Publication number
WO1995009324A1
WO1995009324A1 PCT/DE1994/001049 DE9401049W WO9509324A1 WO 1995009324 A1 WO1995009324 A1 WO 1995009324A1 DE 9401049 W DE9401049 W DE 9401049W WO 9509324 A1 WO9509324 A1 WO 9509324A1
Authority
WO
WIPO (PCT)
Prior art keywords
steam generator
fins
tubes
tube
ribbing
Prior art date
Application number
PCT/DE1994/001049
Other languages
German (de)
English (en)
Inventor
Wolfgang Köhler
Eberhard Wittchow
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Priority to EP94926776A priority Critical patent/EP0720713A1/fr
Priority to JP7509980A priority patent/JPH09503046A/ja
Priority to KR1019960701627A priority patent/KR960705176A/ko
Publication of WO1995009324A1 publication Critical patent/WO1995009324A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/02—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by influencing fluid boundary
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F22B37/101—Tubes having fins or ribs
    • F22B37/103—Internally ribbed tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element

Definitions

  • the invention relates to a steam generator tube with internal ribbing, in the manner of intersecting trains of a first ribbing, an opposing second ribbing is superimposed. It continues to focus on the use of such a steam generator tube in a fossil-fired steam generator.
  • a steam generator the combustion chamber wall of which is constructed from vertically arranged tubes, is more cost-effective to produce than a steam generator having a helical tube.
  • the unavoidable differences in the heat supply to the individual tubes can lead to temperature differences between adjacent tubes - in particular at the outlet of an evaporator. These temperature differences can cause damage due to inadmissible thermal stresses.
  • the temperature differences can be avoided by drastically reducing the friction pressure loss. The reduction in turn is achieved by a corresponding reduction in the flow velocity or the mass flow density in the tubes.
  • the use of internally finned pipes is necessary for this, since these have particularly good heat transfer properties even at low mass flow densities.
  • Pipes of this type with fins forming a multi-start thread on the inside and their use in steam generators are known, for example, from B. from European patent application 0 503 116 known.
  • a steam generator tube, in which a second ribbing is superimposed on one another in the manner of crossing trains, is known from German Offenlegungsschrift 20 32 891.
  • steam generators with a vertically tube-shaped combustion chamber wall are usually operated with relatively high mass flow densities in the internally finned tubes in order to always have a sufficiently high heat transfer from the tube wall to the heat absorption medium, ie to the water / water vapor mixture, in the critical pressure range of approximately 200 to 221 bar , to reach.
  • the heat absorption medium ie to the water / water vapor mixture
  • an additional mixing of the flow in the heat absorption medium can be brought about.
  • This is usually achieved in that the internally finned steam generator tubes have double fins, a first fins being superimposed on opposite fins.
  • the invention is therefore based on the object of designing the inside of the steam generator tubes, in particular the evaporator tubes of a steam generator, in such a way that particularly close to the critical pressure of about 210 bar, a particularly good heat transfer from the tube wall or Heating surface on the heat absorption medium, especially at low mass flow densities, is possible.
  • the resultant surface structure on the inside of the tube favors high turbulence and / or the formation of longitudinal vortices in the medium flowing through the tubes.
  • the additional edges created by the different profile depths of the ribs act when Flow through the heat absorption medium increases turbulence. In other words: as a result of the edge formation, vortex generation is promoted, which in turn brings about a good mixing of the flow, so that overheating of the tube wall is avoided.
  • the invention is based on the consideration that - especially in the vicinity of the critical pressure range above about 200 bar - a flow swirl is not sufficient to ensure good heat transfer. Rather, in addition to a good mixing of the flow to avoid wall overheating of the boundary layer, high turbulence in the flow is necessary. A high level of turbulence in the flow prevents such large vapor bubbles from forming on the heating surface or in the superheated boundary layer that they can combine to form a vapor film and thus worsen the heat transfer.
  • the opposing fins can include the same or different angles with the pipe axis.
  • the first fins advantageously form an acute angle with the pipe axis, while the second fins run parallel to the pipe axis.
  • the steam generator tube then has, in a technically simple manner, a helical ribbing with longitudinal grooves interrupting the ribs.
  • the longitudinal grooves define tear-off edges that favor the generation of eddies.
  • the formation of longitudinal vortices is advantageously also favored in that a flank angle formed by the first or helical ribbing with the tube wall is flatter on the inflow side than on the outflow side.
  • FIG. 1 shows a longitudinal section through a small section of a steam generator tube with opposing internal ribs
  • FIG. 2 shows a detail II from FIG. 1 on a larger scale with an elevation
  • FIG. 3 shows another exemplary embodiment of a steam generator tube having opposed internal ribs
  • FIG. 4 shows a section IV-IV from FIG. 3 on a larger scale with elevations
  • Figure 5 in a simplified representation of a steam generator with a vertically tube-shaped combustion chamber wall.
  • the inside of the steam generator tube is provided with a first rib - in the direction of arrow 2 - which is superimposed on an opposing second rib - in the direction of arrow 4.
  • the opposing ribs 2 and 4 which enclose the angles a and b with the tube axis M, result in a regular structure on the inside with elevations 6 on parallelogram-shaped or rhombic bases and depressions 8, 8 '.
  • Such an elevation 6 with a parallelogram-shaped base area 10 and flattened upper side 12 is shown enlarged in FIG. 2.
  • the angle a is smaller than the angle b.
  • the depressions 8 and 8 ' are of different sizes due to different profile depths s, s' of the ribs 2, 4.
  • the depressions 8 of the first ribs 2 are thus with the elevations 6 'of the opposing second ribbing 4.
  • the steam generator tube has 2 "longitudinal grooves as depressions 8" in addition to a helical internal ribbing.
  • This first ribbing 2 "in turn encloses an acute angle a" with the tube axis M, while the second ribbing 4 "runs parallel to the tube axis M.
  • the longitudinal grooves or depressions 8" in turn provide additional tear-off edges 22 which promote vortex generation.
  • the elevations 6 "of the helical ribbing 2" with the inner tube wall 24 include a flank angle c on the inflow side and a flank angle d on the outflow side.
  • the flank angle c on the inflow side is smaller than or equal to the flank angle d on the outflow side. This favors the formation of longitudinal vortices on the outflow side, as indicated by the arrows 16 ", 18".
  • FIG. 5 schematically shows a steam generator 30 with a rectangular cross section, the vertical throttle cable of which is formed by a surrounding wall 32 which merges into a funnel-shaped bottom 34 at the lower end.
  • a number of burners for a fossil fuel are each in an opening.
  • tion 36 of which only two are visible, in the enclosure or combustion chamber wall 32 composed of the steam generator tubes according to FIGS. 1, 3 or 5.
  • the steam generator tubes 38 are arranged in this region B, in which they are welded together gas-tight to form an evaporator heating surface 40, in a vertically extending manner.
  • Convection heating surfaces 42, 44 and 46 are located above this area B of the gas flue. Above this is a flue gas outlet channel 48, via which the flue gas RG generated by combustion of a fossil fuel leaves the vertical gas flue.
  • the flue gas RG serves as a heating medium for the water or steam mixture flowing in the steam generator tubes 38.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Spray-Type Burners (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
  • Devices For Medical Bathing And Washing (AREA)

Abstract

Afin d'éviter l'ébullition pelliculaire dans des générateurs de vapeur, il est prévu des tuyaux appropriés à structure intérieure nervurée, pour lesquels une seconde couche nervurée (4) est superposée en sens inverse à une première couche nervurée (2). Afin d'améliorer le mélange opéré dans le flux ainsi que le transfert de chaleur à la substance qui absorbe la chaleur (eau, mélange vapeur d'eau) par des turbulences supplémentaires, les couches nervurées orientées en sens contraire (2, 4) comportent selon l'invention différentes hauteurs (s, s').
PCT/DE1994/001049 1993-09-30 1994-09-13 Tuyau de generateur de vapeur a structure interieure nervuree et generateur de vapeur approprie a son utilisation WO1995009324A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP94926776A EP0720713A1 (fr) 1993-09-30 1994-09-13 Tuyau de generateur de vapeur a structure interieure nervuree et generateur de vapeur approprie a son utilisation
JP7509980A JPH09503046A (ja) 1993-09-30 1994-09-13 内側フィン付き蒸気発生器管並びにそれを利用した蒸気発生器
KR1019960701627A KR960705176A (ko) 1993-09-30 1994-09-13 내부에 리브를 갖춘 증기 발생기용 튜브 및 상기 튜브를 사용하는 증기 발생기(internally ribbed tube for a steam generator, and a steam generator using such tubes)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DEP4333403.2 1993-09-30
DE4333403 1993-09-30
DE4339377 1993-11-18
DEP4339377.2 1993-11-18

Publications (1)

Publication Number Publication Date
WO1995009324A1 true WO1995009324A1 (fr) 1995-04-06

Family

ID=25930069

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE1994/001049 WO1995009324A1 (fr) 1993-09-30 1994-09-13 Tuyau de generateur de vapeur a structure interieure nervuree et generateur de vapeur approprie a son utilisation

Country Status (5)

Country Link
EP (1) EP0720713A1 (fr)
JP (1) JPH09503046A (fr)
KR (1) KR960705176A (fr)
CN (1) CN1132549A (fr)
WO (1) WO1995009324A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998022772A1 (fr) * 1996-11-15 1998-05-28 Martin Schade Procede permettant d'ameliorer la transmission de chaleur, et dispositif d'echange de chaleur

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5435460B2 (ja) * 2009-05-28 2014-03-05 古河電気工業株式会社 伝熱管

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2032891A1 (de) * 1969-07-02 1971-02-04 Sumitomo Metal Industries, Ltd , Osaka (Japan) Dampferzeugerrohr und Verfahren zu seiner Herstellung
CA1036804A (fr) * 1976-08-02 1978-08-22 Noranda Mines Limited Methode de formage d'un tube a ailettes dentelees
JPS59119192A (ja) * 1982-12-27 1984-07-10 Hitachi Ltd 伝熱管
JPS6029593A (ja) * 1983-07-27 1985-02-14 Hitachi Ltd 単相流伝熱管構造

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2032891A1 (de) * 1969-07-02 1971-02-04 Sumitomo Metal Industries, Ltd , Osaka (Japan) Dampferzeugerrohr und Verfahren zu seiner Herstellung
CA1036804A (fr) * 1976-08-02 1978-08-22 Noranda Mines Limited Methode de formage d'un tube a ailettes dentelees
JPS59119192A (ja) * 1982-12-27 1984-07-10 Hitachi Ltd 伝熱管
JPS6029593A (ja) * 1983-07-27 1985-02-14 Hitachi Ltd 単相流伝熱管構造

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 8, no. 240 (M - 336)<1677> 6 November 1984 (1984-11-06) *
PATENT ABSTRACTS OF JAPAN vol. 9, no. 152 (M - 391)<1875> 27 June 1985 (1985-06-27) *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998022772A1 (fr) * 1996-11-15 1998-05-28 Martin Schade Procede permettant d'ameliorer la transmission de chaleur, et dispositif d'echange de chaleur

Also Published As

Publication number Publication date
JPH09503046A (ja) 1997-03-25
EP0720713A1 (fr) 1996-07-10
KR960705176A (ko) 1996-10-09
CN1132549A (zh) 1996-10-02

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